Comparative clinical and epidemiological study of hypersensitivity vasculitis versus Henoch-Schönlein purpura in adults.

OBJECTIVES: To assess the incidence and clinical features of adults with hypersensitivity vasculitis (HV) and Henoch-SchOnlein purpura (HSP) in a well-defined population.

METHODS: Retrospective study of an unselected population of adult patients (>20 years) with biopsy-proven cutaneous vasculitis diagnosed as having HV or HSP who presented at a primary hospital between 1988 and 1997. Patients with cutaneous vasculitis secondary to collagen vascular diseases, neoplasia, severe infections, and those with other well-defined clinical entities were excluded. Patients were classified as having either HV or HSP according to the criteria proposed by Michel et al (J Rheumatol 1992;19:721-28).

RESULTS: Fifty-six adults (35 men/21 women), were classified as having HV and 27 adults as having HSP (19 men/8 women). The annual incidence rate for HV was 29.7/million and 14.3/million for HSP. At the onset of the disease, adults with HSP were younger than those with HV (46+/-18 years versus 59+/-18 years in HV; P = .005). Precipitating events were found in 50% of HV and in 30% of HSP patients. A history of drug therapy before the onset of vasculitis was found in 46% of HV and in 26% of HSP (P = .074). At disease onset, skin lesions were the most common manifestation in both groups. During the disease course, adults with HSP had joint manifestations more commonly (59% in HSP v25% in HV; P < .003) and more gastrointestinal (82% v 5% in HV; P < .001) and renal complications (48% v 5% in HV; P < .001). HSP subjects required more aggressive therapy consisting of steroids (P < .001) or cytotoxic agents (P < .001). After 37+/-28 (median, 31) months, complete recovery was observed in 98% of adults with HV. After 40+/-27 (median, 36) months, complete recovery was observed in only 67% of adults with HSP (P < .001). Renal insufficiency was observed in 8% of adults with HSP.

CONCLUSIONS: In adults, HV and HSP as defined by these criteria, behave as two well-differentiated diseases. HV has a milder course and lack of severe complications, and HSP a higher risk of gastrointestinal and renal complications.